In Partition World, Use River to affect landscape.
But editing mode it looks fine. after playing mode, looks like the landscape will streaming low res first,
so the river surface will stay in the low res (looks like broken).
after uncheck the WORLD STREAMING option in world settings menu, all water surface will be fine…
Ok. Solved.
Use the Data Layer and Blue Print to delay the water data loaded after landscape streaming finished.
Water will be fine